In Situ Raman Multi-Gas Sensing During Formation and Residual Gas Impact on Cycling Performance of Pouch Lithium-Ion Batteries

Understanding the impact of residual gases on battery performance after the formation process is crucial for pouch cells. In this study, we investigate the evolution of gases during the formation of pouch batteries and their effects on the cycling performance of the cells after formation. It is found that C2H4, CH4, and CO are generated during the formation process. During battery cycling studies, rapid capacity decay is observed, accompanied by significant gas generation. The findings suggest that residual gases exacerbate internal reactions in the battery, leading to increased gas production and accelerated deterioration of battery performance.